One example of an information collection and storage system to which this invention relates is a vehicular traffic counting recorder. Such traffic recorders are used to record data relating to the number of vehicles passing a given location on a roadway.
In an existing type of traffic recorder, traffic data is stored in the form of perforations on a removable paper tape in the recorder. This type of paper tape recorder is customarily equipped with an electromechanical accumulator and a timer. The electromechanical accumulator totalizes pulses from a traffic-sensing transducer, and on command from the timer, the count total or sum accumulated in the accumulator is periodically punched by mechanical punch equipment on the paper tape in the form of a binary code.
The punched paper tapes in recorders at different roadway locations are customarily collected after several days of field operation and placed in paper tape reader at a data processing center for recovering the stored traffic information. This type of electromechanical traffic counter or recorder has a number of problems and drawbacks.
First, faulty recording operations often occur due to expansion of the paper tape under the influence of environmental conditions. Upon expanding the tape may jam in the punch, tear or otherwise become damaged. Sometimes, only partial holes are punched in the tape for various reasons to result in the improper read-out of data stored on the tape. Because the recorder is often left unattended for several days or more at its roadway location valuable data may be lost due to these faulty operations.
Another drawback of these prior paper tape traffic recorders is that the tape requires carefully handling to avoid damage and resultant loss of data. Furthermore, the data read-out speed of perforated paper tape reader mechanisms is relatively slow as compared with the speed at which stored information may be read out from semiconductor or other electrical memory units.
Additionally the mechanical components of these prior electromechanical traffic recorders require frequent maintenance and tend to be unreliable in operation. These mechanical components also add considerably to the weight and bulk of the recorder and require considerable power for operation. Batteries for this type of traffic recorder are therefore costly.
Another drawback of known electromechanical traffic recorders of the type described above is that the traffic count stored on the paper tape at the end of each time interval set by the timer represents a cumulative total of the counts occurring in all of the preceding timer intervals rather than the count occuring in each individual timer interval. For example, if the counts of 10, 15 and 25 are registered in the first, second and third timer periods, respectively, the count of 10 will first be stored on the tape at the end of the first period, the count of 25 will next be stored on the tape at the end of the second period, and the count of 50 will be finally stored on the tape at the end of the third period. These cumulative count totals require special translator or computer program instructions to recover the individual totals (10, 15 and 25 in the foregoing example) for each timer interval.
The present invention avoids the foregoing problems and drawbacks as well as offering additional advantages as will become apparent from the following summary and detailed description.